Apparatus for holding and centering a tube on a bobbin holder

ABSTRACT

A cap is mounted over the end of the bobbin holder and includes resilient lappets or fingers which are adapted to pass over a rubber ring and be deflected outwardly to frictionally engage the tube. The cap is constructed to roll the rubber ring from an inoperative position within a groove to an operative position in which the ring is resiliently deformed under stress between the cap fingers and bobbin holder.

United States Patent [191 Graf i June 28, 1974 APPARATUS FOR HOLDING AND CENTERING A TUBE ON A BOBBIN HOLDER [75] Inventor: Felix Graf, Winterthur, Switzerland [73] Assignee: Rieter Machine Works, Ltd.,

Winterthur. Switzerland 22 Filed: Feb. 23, 1972 [21] Appl. NO.2 228,711

[30] Foreign Application Priority Data [51] int. Cl B65h 54/54 Blair 1,996,319 4/1935 242/463 UX 2,464,024 3/1949 Carter et al .6 242/462 2,711,863 6/1955 Grettve 242/72 B 2,746,689 5/1956 Berkepeis 242/463 3,081,960 3/1963 Howe 242/462 X Primary Examiner-Stanley N. Gilreath Attorney, Agent, or Firm-Kenyon & Kenyon Reilly Carr & Chapin [5 7] ABSTRACT A cap is mounted over the end of the bobbin holder and includes resilient lappets or fingers which are 58 Field of Search 242/464, 46.2, 46.3, 46.6, adapted to p Over a rubber ring and be deflected 242/72 72 1295 129 7 129 30 outwardly to frictionally engage the tube. The cap is 130.1, 72 B; 279/2; 285/214, 322, 344, 345; Constructed to roll the rubber ring from an inoperative 2 752 0 53 103 12 position within a groove to an operative position in which the ring is resiliently deformed under stress be- 5 References Cited tween the cap fingers and bobbin holder.

UNITED STATES PATENTS 1,884,805 10/1932 Moritz 242/462 16 Claims, 6 Drawing Figures i I 7 l4 9 4\ 2t. 6 ll 5 a APPARATUS FOR HOLDING AND CENTERING A TUBE ON A BOBBIN HOLDER This invention relates to an apparatus for holding and centering a tube on a bobbin holder. More particularly, this invention relates to an apparatus for holding and centering a tube on a bobbin holder of a take-up machine for endless filaments, a drawtwisting machine and a spinning and twisting machine.

Bobbin holders for various types of machines have been known on which a tube can be mounted. In some instances, the tube has been mounted at one end i.e. the rest side, so as to be axially retained and centered by means of a rubber ring of round cross-section. Generally. the rubber ring has been'rolled into an inclined groove as the tube is donned onto the holder. The other end of the tube has been centered at the free end of the bobbin holder by means of a ring made from high-raise plush or a ring-shaped metallic sliding surface.

However, in the case of the plush ring, in order to ensure sufficient centering action, the ring must be chosen with such a diameter that the tube can be donned only under the application of considerable force. Furthermore, the plush cover becomes flatened out after a period of operation and thus can no longer ensure sufficient centering action. In the case of the metallic ring-shaped sliding surface, if the differences between the tube and the sliding surface diameters are kept small in order to ensure correct centering, any noticeable constriction of the tube during the package build would simultaneously increase the adhesion between the bobbin holder and the tube. Thus, the full bobbin could no longer be doffed from the bobbin holder unless considerable force is used.

Instead of using the above mentioned devices, proposals have been made for using rubber rings of circular cross-section for holding and centering the tube on the bobbin holder which are deformed between inclined ring bodies by means of a tensioning device in such manner that the rubber rings are pressed against the inside of the tube to generate the adhesion friction needed for holding the tube. However, these devices require an additional tensioning device. Also, the ring bodies, in relation to the bobbin chuck of the bobbin holder, are friction bodies which are subject to wear. Further, the deformation of the rubber rings does not always ensure correct centering and the diameter of the bobbin chuck of the bobbin holder which takes up the stresses must be made smaller, and thus weaker, due to the pressure of the ring bodies between the tube and the bobbin chuck.

Accordingly, it is an object of the invention to pro vide a simple means for holding and centering a tube on a bobbin holder.

It is another object of the invention to ensure a precise centering of a tube on a bobbin holder.

It is another object of the invention to provide a substantially wear-free means for holding and centering a tube on a bobbin.

It is another object of the invention to allow doffing ofa wound tube from a bobbin holder in a simple manner even if constricted during winding.

It is another object of the invention to provide for centering and holding of a tube on a bobbin holder by a common means.

Briefly, the invention is directed to an apparatus for centering and holding a tube on a bobbin holder. The apparatus includes an elastic ring shaped element which is mounted within an annular groove near the free end of the bobbin holder and a cap which is slidably mounted over the free end of the bobbin holder. The cap is provided with a spring-like portion, such as a plurality of resilient lappets or fingers, which extend generally axially of the bobbin holder. In addition, the spring-like portion is contoured on the inside surface so as to initially engage and then pass over the elastic ring as the ring is caused to roll out of the groove in the bobbin holder as the cap is slid inwardly along the holder. This portion also defines an interior recess or portion into which the elastic ring is moved after being rolled out of the groove of the holder.

The elastic ring is of circular crosssection and is disposed so as to be slid or rolled along the outer surface of the bobbin holder between an idle position, in the groove, and an operating position. In the operating position, the ring is deformed between the spring-like portion of the cap and the bobbin holder while also enlarging the spring-like portion of the cap in order to generate a uniformly distributed circumferential centering and holding force against a tube.

The bobbin holder and cap are also each provided with a protrusion which mate with each other after the cap is placed on the bobbin holder so as to ensure against accidental removal of the cap.

In use, the cap is initially in an extended position relative to the bobbin holder and the elastic ring is in the groove of the holder. Once an empty tube is donned onto the holder, the cap is moved inwardly of the holder and tube to expand and engage the interior of the tube. The tube is thus centered and held in place simultaneously.

In order to doff a wound tube from the bobbin holder, the tube is grasped and pulled axially outwardly. The friction force between the tube and cap then causes the cap to also move outwardly. Alternatively, the capcan be constructed? so as to be pulled independently along the bobbin holder. To this end, the cap can cooperate with a suitable pulling key or can have a suitable handle thereon. Also, a pressurized medium can be used to move the cap. In this latter case, the medium can be delivered via the interior of the holder intoa space between the cap and holder.

These and other objects and advantages of the invention will become more apparent from the following detailed description and appended claims taken in con junction with the accompanying drawings in which:

FIG. 1 illustrates a cross-sectional view of an apparatus of the invention in use between a bobbin holder and a tube;

FIG. 2 illustrates a cross-sectional view of the cap of FIG. 1 in an extended position relative to the bobbin holder;

FIG. 3 illustrates a cross-sectional view of a modified cap according to the invention;

FIG. 4 illustrates an exploded view of a key and a cap according to the invention;

FIG. 5. illustrates a cross-sectional view of a cap having a handle according to the invention; and

FIG. 6 illustrates another embodiment of a cap according to the invention.

Referring to FIG. 1, a bobbin holder 1 which is hollow over the entire length and which is arranged on a machine such as a take-up machine for an endless filament, a drawtwister, or a spinning and twisting machine (as indicated by dash-dot lines) has a cylindrical tube 2 donned thereon for winding up a bobbin 24. The end of the bobbin holder 1 facing the machine has a perpendicularlly disposed surface which serves as a rest 3 and a cylindrical surface 4 which provides for centering of the tube 2. In the vicinity of the free end, the bobbin holder 1 is provided with a circumferential recess 5 and with an adjacent cylindrical surface 6. In addition, a protrusion 8 which functions as a rest extends radially from near the end of the bobbin holder 1.

A rubber ring 7 of circular cross-section is positioned on the cylindrical surface 6 in an operating position after being moved from an idling position in the recess 5.

A cap 9 is mounted over the end of the bobbin holder 1 and within the bore of the tube 2. The cap includes a spring-like zone or portion which extends over the rubber ring 7 and engages against the inside of the tube 2. As shown, this springlike portion of the cap 9 includes a plurality of axial slots 10 which define circumferentially spaced lappets or fingers 11 which extend from a cup-like portion of the cap 9. The cap 9 is made of a suitable material so that the lappets 11 are resilient. Each lappet 11 has a conical surface 112 at the open end of the cap 9 as well as an internal recess 13a (FIG. 2) for taking up the rubber ring 7 in the operating position of the ring 7. The cap 9 also has a protrusion 14 which serves to limit the recess 13 as well as to act as a counter-rest for the protrusion 8 of the bobbin holder 1. The inside diameter of the protrusion 14 is thus smaller than the outside diameter of the protrusion 8.

Referring to FIG. 2, in use, the cap 9 is initially in an extended position from the end of the bobbin holder 1 prior to donning of a tube 2. In this position, the rubber ring 7 is disposed within the groove 5 of the holder 1. The tube 2 is then pushed onto the bobbin holder 1 until becoming practically flush with the extended cap 9 (FIG. 2). Both the tube 2 and the cap 9 are then simultaneously pushed further towards the left as viewed. During this time, the cap 9 abuts the rubber ring 7 located in the recess 5 and rolls the rubber ring 7 out of the recess 5 by means of the cone surface 12 onto the surface 6. The cap 9 rolls the ring 7 until the ring 7 reaches an end position in the recess 13 arranged in the resilient lappets 11 (FIG. 1). In this position, the tube 2 abuts at the side of the bobbin holder I facing the machine against the rest 3 and is centered thereat by the surface 4. Also, at the free end of the bobbin holder 1, the tube 2 is radially centered as the rubber ring 7 is pressed between the surface 6 of the holder 1 and the recess 13 of the cap 9 and presses the resilient lappets 11 against the inside wall of the tube 2. Also, the adhesional friction needed for the lappets 10 to axially hold the tube 2 is generated by the outward deflection of the lappets 10. As shown in FIG. 2, the outer diameter of the cap 9 is slightly less than the inner diameter of the tube 2.

In order to effect an additional force of the tube 2 against the rest 3, the distance between the position A (FIG. 2), Le. the center line of the recess 5, and the position B (FIG. 1), i.e. the center line of the rubber ring 7 in the operating position, is chosen to be somewhat smaller than the natural rolling distance of the ring 7 about its profile axis from one idling position to the other. This natural rolling distance corresponds to the diameter and structure of the ring 7. However, the distance between the two portions A and B is larger than half this natural rolling distance. In this manner, an inner tension remains in the rubber ring 7 tending to complete the rolling process and, thus, results in a force directed towards the rest 3 and transmitted via the cap 9 by means of adhesional friction on the tube 2.

Doffing of the full bobbin 24 is effected in the following manner:

The full bobbin 24 is gripped by hand and is doffed axially. The cap 9 is thus pulled back and rolls the rubber ring 7 back into the initial position A (FIG. 2) so that the resilient lappets 11 move back into their normal position and loosen the connection with the tube 2. The protrusion 8 and the protrusion 14 prevent complete removal of the cap 9 from the bobbin holder 1. However, as the protrusion 14 is arranged on the resilient lappets 10, the cap 9, if needed, can be removed from the bobbin holder 1 over the protrusion 8 with a small force.

Referring to FIG. 3, a cap 16 can also be made with a gripping means such as a circular opening 17 in the cup-like portion so as to facilitate retraction or removal.

Referring to FIG. 4, a cap 118 can be provided with a profiled opening 19 in the cup-like portion so as to cooperate with a profiled portion 20 of a key 21 for retraction purposes.

Referring to FIG. 5, the cap 22 can have an integral gripping means in the form of a handle 23 projecting therefrom to facilitate retraction.

Referring to FIG. 6, instead of forming a recess in the cap 6 to receive the rubber ring as shown in FIG. 1, the cap can be formed with a flat circumferential surface 13b to receive the rubber ring. This surface 13b extends to a protrusion 14 as described above.

Referring to FIGS. 3 and 5, during use, in order to doff a bobbin, the cap 16 (FIG. 3) or 22 (FIG. 5), respectively, is manually retracted. This causes the bobbin tube to be carried along at least until the protrusion 14 on the lappets ll rests against the protrusion 8 of the bobbin holder. Thus, the connection between the cap and the tube is loosened and the full bobbin can be removed completely.

Referring to FIG. 4, in order to doffa bobbin, the key profile 20 of the key is inserted through the opening 19 and upon rotation of e.g. degrees, the cap 18 is pulled out by means of the key 21, until the protrusion 14 on the lappets ll rests against the protrusion 8 of the bobbin holder. Thus, the connection between the cap and the tube is loosened and the full bobbin can be doffed completely.

Referring to FIG. I, the cap 9 can alternatively be retracted through the use of a pressure medium. For example, with the cap 9 sealingly disposed over the open end of the holder 1, the hollow room within the bobbin holder 1 can be pressurized by means of the pressure medium to cause the cap 9 to move axially until the protrusion 14 on the lappets 11 rests against the protrusion 8 of the bobbin holder 1. The connection between the cap 9 and the tube 2 is thus loosened and the full bobbin can be taken off completely. A connection 24 for introducing the pressure medium can be suitably provided at the opposite end of the holder 1.

The invention thus provides an apparatus which is of simple construction and manufacture. In addition, the operation of the apparatus is simple. That is, without exerting strong force, the cap can be displaced parallel with the tube for the tensioning process as well as for the loosening process. Also, as this displacement does not cause friction between these elements, the elements are not subject to wear. Furthermore, the tube is freely removable even in case it is constricted during a winding process.

Finally. the invention provides an apparatus which effects both radial centering and axial holding by the same common means.

What is claimed is:

1. In combination with a bobbin holder having a circumferential groove and an adjacent surface, an elastic ring engaging said holder for selective positioning within said groove and on said surface, and a tube disposed over said holder; a cap disposed over an end of said holder, said cap having a spring-like portion disposed between said ring and said tube and resiliently deflected against said tube to center and axially hold said tube on said holder when said ring is positioned on said surface, said ring releasing said spring-like portion from holding engagement with said tube when said ring is positioned in said groove.

2. The combination as set forth in claim 1 wherein said spring-like portion includes an internal recess for receiving said ring therein with said ring on said surface of said bobbin holder.

3. The combination as set forth in claim 2 wherein said recess is of a depth and width to permit said elastic element to freely extend therein.

4. The combination as set forth in claim 2 wherein the distance from the center line of said groove in said bobbin holder to the center line of the position of said ring on said surface is smaller than the natural rolling distance of said ring about the profile axis of said ring but larger than half said rolling distance whereby said ring generates a force directed axially towards an end of said bobbin holder opposite said cap.

5. The combination as set forth in claim 1 wherein said ring is of circular cross-section and is a rubber ring.

6 The combination as set forth in claim 1 wherein said bobbin holder has a radial protrusion at said end and said cap has an internal radial protrusion of smaller inner diameter than the outer diameter of said protrusion on said bobbin holder.

7. The combination as set forth in claim 1 wherein said internal radial protrusion is in said spring-like portion of said cap.

8. The combination as set forth in claim 1 wherein said spring-like portion includes a plurality of axial slots.

9. The combination as set forth in claim 1 wherein said spring-like portion has a conical surface at an open end of a diameter which decreases towards the inside.

13. The combination as set forth in claim 12 wherein said opening is round.

14. The combination as set forth in claim 12 wherein said opening is profiled to receive a correspondingly profiled key.

15. The combination as set forth in claim 11 wherein said gripping means is an integral handle on said cap oriented towards the outside.

16. The combination as set forth in claim 1 wherein said bobbin holder is open at said end and said cap sealingly engages over said holder, and which further includes a connection for a pressure medium at an opposite end. 

1. In combination with a bobbin holder having a circumferential groove and an adjacent surface, an elastic ring engaging said holder for selective positioning within said groove and on said surface, and a tube disposed over said holder; a cap disposed over an end of said holder, said cap having a spring-like portion disposed between said ring and said tube and resiliently deflected against said tube to center and axially hold said tube on said holder when said ring is positioned on said surface, said ring releasing said spring-like portion from holding engagement with said tube when said ring is positioned in said groove.
 2. The combination as set forth in claim 1 wherein said spring-like portion includes an internal recess for receiving said ring therein with said ring on said surface of said bobbin holder.
 3. The combination as set forth in claim 2 wherein said recess is of a depth and width to permit said elastic element to freely extend therein.
 4. The combination as set forth in claim 2 wherein the distance from the center line of said groove in said bobbin holder to the center line of the position of said ring on said surface is smaller than the natural rolling distance of said ring about the profile axis of said ring but larger than half said rolling distance whereby said ring generates a force directed axially towards an end of said bobbin holder opposite said cap.
 5. The combination as set forth in claim 1 wherein said ring is of circular cross-section and is a rubber ring.
 6. The combination as set forth in claim 1 wherein said bobbin holder has a radial protrusion at said end and said cap has an internal radial protrusion of smaller inner diameter than the outer diameter of said protrusion on said bobbin holder.
 7. The combination as set forth in claim 1 wherein said internal radial protrusion is in said spring-like portion of said cap.
 8. The combination as set forth in claim 1 wherein said spring-like portion includes a plurality of axial slots.
 9. The combination as set forth in claim 1 wherein said spring-like portion has a conical surface at an open end of a diameter which decreases towards the inside.
 10. The combination as set forth in claim 1 wherein said spring-like portion includes a flat circumferential surface extending from the open end of said cap to engage said ring.
 11. The combination as set forth in claim 1 wherein said cap includes a gripping means thereon.
 12. The combination as set forth in claim 11 wherein said cap has an opening forming said gripping means.
 13. The combination as set forth in claim 12 wherein said opening is round.
 14. The combination as set forth in claim 12 wherein said opening is profiled to receive a correspondingly profiled key.
 15. The combination as set forth in claim 11 wherein said gripping means is an integral handle on said cap oriented towards the outside.
 16. The combination as set forth in claim 1 wherein said bobbin holder is open at said end and said cap sealingly engages over said holder, and which further includes a connection for a pressure medium at an opposite end. 